A conventional method of fabricating wood trusses with toothed metal plates connecting the joints is to assemble the components on a horizontal bed with plates on the top side of the joints, pass a traveling or gantry pressure roll over the assembled truss, then manually invert the truss, apply plates to the other side of the joints, and pass the roll over the truss a second time, after which the completed truss is slid laterally off the bed. A variation of this method is to apply plates simultaneously to both sides of the joints, pass the traveling roll over the assembly to preliminarily set the teeth, and then pass the assembly through a stationary set of pinch rolls to fully embed the teeth of the plates. This latter method is disclosed in my prior U.S. Pat. No. 3,212,694.
Either of these methods involves two roll passes and excessive time and labor in assembling and handling the trusses.
More recently, I have developed a method and apparatus, as shown in my prior U.S. Pat. No. 3,868,898, whereby the truss components are assembled on a flexible horizontal jig bed designed to fully embed the teeth of the connector plates by a single pass of the bed and truss through traveling pinch rolls. However, this apparatus is complicated and expensive, and requires close tolerances with respect to the relationship between the thickness of the bed and the bight of the rolls.